diff --git a/lib/utils/pkcs7-padding.js b/lib/utils/pkcs7-padding.js
--- a/lib/utils/pkcs7-padding.js
+++ b/lib/utils/pkcs7-padding.js
@@ -16,6 +16,56 @@
 
 import invariant from 'invariant';
 
+export type PaddingConfiguration = {
+  +blockSizeBytes: number,
+  +superblockSizeBlocks: number,
+};
+
+/**
+ * The padding configuration for 10KB superblocks.
+ * The block size is 250 bytes, and the superblock size is 40 blocks.
+ */
+export const PKCS7_10KB: PaddingConfiguration = {
+  blockSizeBytes: 250,
+  superblockSizeBlocks: 40,
+};
+
+/**
+ * Pads the input using the extended PKCS#7 padding (superblock padding).
+ * The input is first padded using the standard PKCS#7 padding, and then
+ * padded to the nearest multiple of superblocks (blocks of blocks).
+ *
+ * @param {Uint8Array} data - The input to be padded.
+ * @param {PaddingConfiguration} paddingConfiguration - The padding
+ * configuration. Defaults to multiple of 10KB. See {@link PKCS7_10KB}.
+ * @returns {Uint8Array} The padded input.
+ */
+export function pad(
+  data: Uint8Array,
+  { blockSizeBytes, superblockSizeBlocks }: PaddingConfiguration = PKCS7_10KB,
+): Uint8Array {
+  const pkcs7Padded = pkcs7pad(data, blockSizeBytes);
+  return superblockPad(pkcs7Padded, blockSizeBytes, superblockSizeBlocks);
+}
+
+/**
+ * Unpads the input using the extended PKCS#7 padding (superblock padding).
+ * The input is first unpadded on the block basis, and then unpadded using
+ * the standard PKCS#7 padding.
+ *
+ * @param {Uint8Array} data - The input to be unpadded.
+ * @param {PaddingConfiguration} paddingConfiguration - The padding
+ * configuration. Defaults to multiple of 10KB. See {@link PKCS7_10KB}.
+ * @returns {Uint8Array} The unpadded input.
+ */
+export function unpad(
+  data: Uint8Array,
+  { blockSizeBytes }: PaddingConfiguration = PKCS7_10KB,
+): Uint8Array {
+  const blockUnpadded = superblockUnpad(data, blockSizeBytes);
+  return pkcs7unpad(blockUnpadded);
+}
+
 /**
  * PKCS#7 padding function for `Uint8Array` data.
  *
@@ -23,7 +73,7 @@
  * @param {number} blockSizeBytes - The block size in bytes.
  * @returns {Uint8Array} The padded data as a new Uint8Array.
  */
-export function pkcs7pad(data: Uint8Array, blockSizeBytes: number): Uint8Array {
+function pkcs7pad(data: Uint8Array, blockSizeBytes: number): Uint8Array {
   invariant(blockSizeBytes > 0, 'block size must be positive');
   invariant(blockSizeBytes < 256, 'block size must be less than 256');
   const padding = blockSizeBytes - (data.length % blockSizeBytes);
@@ -40,7 +90,7 @@
  * @returns {Uint8Array} The unpadded data as a new Uint8Array.
  * @throws {Error} If the padding is invalid.
  */
-export function pkcs7unpad(data: Uint8Array): Uint8Array {
+function pkcs7unpad(data: Uint8Array): Uint8Array {
   const padding = data[data.length - 1];
   invariant(padding > 0, 'padding must be positive');
   invariant(data.length >= padding, 'data length must be at least padding');
@@ -63,7 +113,7 @@
  * @param {number} superblockSize - The superblock size in blocks.
  * @returns {Uint8Array} The block-padded data as a new Uint8Array.
  */
-export function superblockPad(
+function superblockPad(
   data: Uint8Array,
   blockSizeBytes: number,
   superblockSize: number,
@@ -96,10 +146,7 @@
  * @param {number} blockSizeBytes - The block size in bytes.
  * @returns {Uint8Array} - The unpadded data as a new Uint8Array.
  */
-export function superblockUnpad(
-  data: Uint8Array,
-  blockSizeBytes: number,
-): Uint8Array {
+function superblockUnpad(data: Uint8Array, blockSizeBytes: number): Uint8Array {
   invariant(blockSizeBytes > 0, 'block size must be positive');
   invariant(blockSizeBytes <= 255, 'block size must be less than 256');
   invariant(
@@ -121,3 +168,11 @@
   const unpaddedData = data.subarray(0, unpaddedLengthBytes);
   return unpaddedData;
 }
+
+// exported for testing purposes only
+export const testing = {
+  pkcs7pad,
+  pkcs7unpad,
+  superblockPad,
+  superblockUnpad,
+};
diff --git a/lib/utils/pkcs7-padding.test.js b/lib/utils/pkcs7-padding.test.js
--- a/lib/utils/pkcs7-padding.test.js
+++ b/lib/utils/pkcs7-padding.test.js
@@ -1,11 +1,7 @@
 // @flow
 
-import {
-  pkcs7pad,
-  pkcs7unpad,
-  superblockPad,
-  superblockUnpad,
-} from './pkcs7-padding.js';
+import type { PaddingConfiguration } from './pkcs7-padding';
+import { pad, unpad, testing } from './pkcs7-padding.js';
 
 describe('PKCS#7 Padding', () => {
   it('should pad data to a multiple of blockSize bytes', () => {
@@ -13,7 +9,7 @@
     const data = generateRandomData(100);
     const expectedPadding = 16 - (data.length % blockSize);
 
-    const padded = pkcs7pad(data, blockSize);
+    const padded = testing.pkcs7pad(data, blockSize);
     expect(padded.length % 16).toBe(0);
     expect(padded[padded.length - 1]).toBe(expectedPadding);
   });
@@ -23,15 +19,15 @@
     const data = generateRandomData(16);
     const expectedPadding = 16;
 
-    const padded = pkcs7pad(data, blockSize);
+    const padded = testing.pkcs7pad(data, blockSize);
     expect(padded.length % 16).toBe(0);
     expect(padded[padded.length - 1]).toBe(expectedPadding);
   });
 
   it('pkcs7pad should fail if blockSize is out of 1-255 range', () => {
     const data = generateRandomData(16);
-    expect(() => pkcs7pad(data, 0)).toThrow();
-    expect(() => pkcs7pad(data, 256)).toThrow();
+    expect(() => testing.pkcs7pad(data, 0)).toThrow();
+    expect(() => testing.pkcs7pad(data, 256)).toThrow();
   });
 
   it('pkcs7unpad should unpad data', () => {
@@ -41,7 +37,7 @@
       ...[6, 6, 6, 6, 6, 6],
     ]);
 
-    const unpadded = pkcs7unpad(padded);
+    const unpadded = testing.pkcs7unpad(padded);
     expect(unpadded.length).toBe(10);
   });
 
@@ -51,7 +47,7 @@
       ...generateRandomArray(10),
       ...[0, 0, 0, 0, 0, 0],
     ]);
-    expect(() => pkcs7unpad(padded)).toThrow();
+    expect(() => testing.pkcs7unpad(padded)).toThrow();
   });
 
   it('pkcs7unpad should throw if the padding length is > blockSize', () => {
@@ -60,7 +56,7 @@
       ...generateRandomArray(10),
       ...[17, 17, 17, 17, 17, 17],
     ]);
-    expect(() => pkcs7unpad(padded)).toThrow();
+    expect(() => testing.pkcs7unpad(padded)).toThrow();
   });
 
   it('pkcs7unpad should throw if the padding is invalid', () => {
@@ -69,14 +65,14 @@
       ...generateRandomArray(10),
       ...[6, 1, 2, 3, 4, 6],
     ]);
-    expect(() => pkcs7unpad(padded)).toThrow();
+    expect(() => testing.pkcs7unpad(padded)).toThrow();
   });
 
   it('pkcs7pad and pkcs7unpad should be inverses', () => {
     const blockSize = 16;
     const data = generateRandomData(100);
-    const padded = pkcs7pad(data, blockSize);
-    const unpadded = pkcs7unpad(padded);
+    const padded = testing.pkcs7pad(data, blockSize);
+    const unpadded = testing.pkcs7unpad(padded);
     expect(unpadded.length).toBe(data.length);
     expect(unpadded).toEqual(data);
   });
@@ -91,7 +87,11 @@
     const expectedBlockPadding = 1;
 
     const data = generateRandomData(dataLengthBytes);
-    const padded = superblockPad(data, blockSizeBytes, superblockSizeBlocks);
+    const padded = testing.superblockPad(
+      data,
+      blockSizeBytes,
+      superblockSizeBlocks,
+    );
 
     expect(padded.length % expectedPaddedLength).toBe(0);
     expect(padded[padded.length - 1]).toBe(expectedBlockPadding);
@@ -105,7 +105,11 @@
     const expectedBlockPadding = 4;
 
     const data = generateRandomData(dataLengthBytes);
-    const padded = superblockPad(data, blockSizeBytes, superblockSizeBlocks);
+    const padded = testing.superblockPad(
+      data,
+      blockSizeBytes,
+      superblockSizeBlocks,
+    );
 
     expect(padded.length % expectedPaddedLength).toBe(0);
     expect(padded[padded.length - 1]).toBe(expectedBlockPadding);
@@ -120,7 +124,7 @@
       ...new Array(2 * 16).fill(2),
     ]);
 
-    const unpadded = superblockUnpad(padded, blockSizeBytes);
+    const unpadded = testing.superblockUnpad(padded, blockSizeBytes);
 
     expect(unpadded.length).toBe(32);
     expect(unpadded).toEqual(padded.subarray(0, 32));
@@ -132,7 +136,7 @@
       ...generateRandomArray(2 * 16),
       ...new Array(2 * 16).fill(0),
     ]);
-    expect(() => superblockUnpad(padded, blockSizeBytes)).toThrow();
+    expect(() => testing.superblockUnpad(padded, blockSizeBytes)).toThrow();
   });
 
   it('superblockUnpad should throw if the padding length is > num blocks', () => {
@@ -142,7 +146,7 @@
       ...generateRandomArray(2 * 16),
       ...new Array(2 * 16).fill(5),
     ]);
-    expect(() => superblockUnpad(padded, blockSizeBytes)).toThrow();
+    expect(() => testing.superblockUnpad(padded, blockSizeBytes)).toThrow();
   });
 
   it('superblockUnpad should throw if the padding is invalid', () => {
@@ -152,7 +156,67 @@
       ...generateRandomArray(2 * 15),
       ...[1],
     ]);
-    expect(() => superblockUnpad(padded, blockSizeBytes)).toThrow();
+    expect(() => testing.superblockUnpad(padded, blockSizeBytes)).toThrow();
+  });
+});
+
+describe('padding integration tests (pad and unpad)', () => {
+  it('should pad data to a multiple of superblockSize blocks', () => {
+    const config: PaddingConfiguration = {
+      blockSizeBytes: 16,
+      superblockSizeBlocks: 4,
+    };
+
+    // 20 bytes of data - expected 4 blocks total (1 superblock):
+    // - block 1 (16 bytes) = 16 bytes of data
+    // - block 2 (16 bytes) = 4 bytes of data (remaining 12 bytes of padding)
+    // - block 3 (16 bytes) = full padding (filled with 2s)
+    // - block 4 (16 bytes) = full padding (filled with 2s)
+    const dataLengthBytes = 20;
+    const expectedPkcs7Padding = 12;
+    const expectedBlockPadding = 2;
+    const expectedPaddedLength = 4 * 16;
+
+    const data = generateRandomData(dataLengthBytes);
+    const padded = pad(data, config);
+
+    expect(padded.length % expectedPaddedLength).toBe(0);
+    expect(padded[padded.length - 1]).toBe(expectedBlockPadding);
+    expect(padded[2 * 16 - 1]).toBe(expectedPkcs7Padding);
+  });
+
+  it('pad should add a full superblock if pkcs7-padded input is a multiple of superblockSize blocks', () => {
+    const config: PaddingConfiguration = {
+      blockSizeBytes: 16,
+      superblockSizeBlocks: 4,
+    };
+
+    // 5 bytes less so pkcs7 padding is 5 bytes and pads equally to superblock
+    // size
+    const pkcs7paddingLength = 5;
+    const dataLengthBytes = 4 * 16 - pkcs7paddingLength;
+
+    const expectedPaddedLength = 8 * 16;
+    const expectedBlockPadding = 4;
+
+    const data = generateRandomData(dataLengthBytes);
+    const padded = pad(data, config);
+
+    expect(padded.length % expectedPaddedLength).toBe(0);
+    expect(padded[padded.length - 1]).toBe(expectedBlockPadding);
+  });
+
+  it('pad and unpad should be inverses', () => {
+    const config: PaddingConfiguration = {
+      blockSizeBytes: 16,
+      superblockSizeBlocks: 4,
+    };
+
+    const data = generateRandomData(100);
+    const padded = pad(data, config);
+    const unpadded = unpad(padded, config);
+    expect(unpadded.length).toBe(data.length);
+    expect(unpadded).toEqual(data);
   });
 });